A batch of up to 100,000 20p pieces were shipped from the Royal Mint earlier this year without the 2009 date stamp. Bidders on eBay have been offering up to £240 for one of the coins while some sellers have been asking as much as £5,000.

Alloy Cupro Nickel . These Irish shilling coins had no silver content after 1951 Threr were no Irish one shilling coins minted after 1968

These earlier coins (per 1951) were noticeably different from their later counterparts as they were of a lighter hue than the copronicle coins minted from 1951, and they resisted wear less well. The cupronickel coin contained 75% copper and 25% nickel. These coins had no silver content.

The coin measured 0.935 inches (23.7 mm) in diameter and weighed 5.655 grams: this did not change with cupro-nickel coin. The last shillings were minted in 1968. When the currency was decimalised, this coin continued to circulate alongside its replacement five pence (which also featured a bull on the reverse); the shilling was finally withdrawn from circulation on 1 January 1993 as a smaller five pence coin was introduced.

The reverse design featuring a bull was designed by English artist Percy Metcalfe The PM on the right over scilling is the designers initials The obverse featured the Irish Harp From 1938 to 1968 the inscription changed to éire on the left of the harp and the date on the right.